Cyber Resilience

CVE-2026-54274

DoS in Aiohttp ≤ 3.14.1

Published
22 June 2026
Modified
26 June 2026
Patch / advisory
CVSS Score v4 6.6
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0031 23th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2026-54274 is a medium-severity Allocation of Resources Without Limits or Throttling (CWE-770) vulnerability in Aiohttp Aiohttp. Its CVSS base score is 6.6 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 23th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SC-5 (Denial-of-service Protection) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.1, if an attacker sends large incomplete websocket frame payloads, it may be possible to bypass the usual size limits on memory use. This vulnerability is fixed…

more

in 3.14.1.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
Why these techniques?

Remote memory exhaustion via malformed websocket frames directly enables exploitation of a public-facing application (T1190) resulting in endpoint DoS through application exploitation (T1499.004).

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2025-69228Same product: Aiohttp Aiohttp
CVE-2026-54277Same product: Aiohttp Aiohttp
CVE-2025-69223Same product: Aiohttp Aiohttp
CVE-2025-69229Same product: Aiohttp Aiohttp
CVE-2026-34517Same product: Aiohttp Aiohttp
CVE-2026-34513Same product: Aiohttp Aiohttp
CVE-2026-34516Same product: Aiohttp Aiohttp
CVE-2026-22815Same product: Aiohttp Aiohttp
CVE-2025-69227Same product: Aiohttp Aiohttp
CVE-2026-54273Same product: Aiohttp Aiohttp

Affected Assets

aiohttp
aiohttp
≤ 3.14.1

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • SC-5 Denial-of-service Protection
  • SI-10 Information Input Validation
Detect
Catch it (NIST detect / respond)
  • SI-4 System Monitoring
Harden
Shrink the surface (DISA STIG)
  • 5 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V15.4.4

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly enforces resource limits and throttling to block memory exhaustion from oversized or incomplete WebSocket frames.

prevent

Requires validation of all inputs to enforce frame-size and completeness checks that the vulnerable AIOHTTP parser bypassed.

detect

Enables monitoring of memory and connection state to identify anomalous resource consumption from incomplete frames.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.IR-04 mostly match
degrades

Monitoring capacity and taking action to maintain availability directly reduces unchecked resource allocation.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

detects

Baseline comparison of CPU, memory and bandwidth usage helps surface uncontrolled resource allocations before they cause service degradation.

prevents

Capacity projections and elasticity measures ensure that allocation requests are bounded and can be throttled, reducing the window in which an attacker can force unbounded resource reservations.

mitigates

Defining retention periods and deletion schedules for backup copies prevents indefinite accumulation of data on storage media without corresponding resource-management controls.

mitigates

Architectural redundancy and automatic failover limit the impact of an attacker who forces excessive allocations, because spare capacity can absorb the load until the primary instance recovers.

none

Documented incident response procedures that include activation of continuity plans and controlled recovery help ensure that resource consumption triggered by an incident is bounded and managed rather than left unbounded.

none

Mandating tested continuity procedures that preserve or replace resource-limiting controls prevents an attacker from exploiting the absence of throttling mechanisms during an outage.

References